This describes the electron gun power as 10 Megawatts. In WB6 at least, the electron guns were a ~ 12 volts, not 12,000 volts. I'm not certain what the current was as it was a dynamic runaway process with time. But during the time Beta = ~ 1 phase the electron gun current was ~ 40 amps (40 amps X 12 volts = 480 watts). The electrons were then accelerated by the 12,000 volt potential on the magrids. I'm not sure where the 5 amp current on the magrids comes from. I speculate that a 40 amp electron current being accelerated by a 12,000 volt potential that is supported by a meager 5 amp power supply would rersult in a significant voltage drop. In any case, 40 amps of electron current (at Beta=1) that is accelerated by a 12,000 volt potential would result in 480,000 watts electron input power. Only when the system was breaking down with glow discharge/ arching did the non regulated capacitor bank deliver the current in the hundreds of amps (while it was short circuiting).

I'm assuming that the this power (480,000 watts) plus the magnetic
power (~10,000 watts) is the baseline for WB6 (with ~ 1 milliwatt of fusion power output) that serves as the basis for scaling to other machines.